Apparatus for automatic laying of wire ties

ABSTRACT

The invention concerns an apparatus including a body equipped with means supplying a continuous wire, feeding said wire to a curved slot capable of being closed on itself, a twister driven in rotation during the process and a wire cutting device to form a tie. Said apparatus further comprises a first motor for driving the wire and for closing and opening the guide slot and a second motor for actuating the twister and the wire cutting device. Control means successively drive the wire and close the slot with the first motor, then, the first motor being switched off, simultaneously drive the wire cutting device and the twister with the second motor, and finally, after the second motor is switched off, open the slot and feed the latter with wire.

TECHNICAL FIELD OF INVENTION

The subject of the present invention is an appliance for the automaticfitting of twisted ties, for example for the attachment of vine shootsor of plant branches to supports, such as stakes or training wires.

Each appliance may also be used for other applications, in particularindustrial applications, requiring the tying of two pieces of smallcross section, in particular of filamentary pieces.

BACKGROUND OF INVENTION

In the agricultural sector, it is often necessary to attach a plant to asupport, in order to guide it as it grows. Thus, in particular, it isknown to attach vine shoots, generally to hori ontal wires calledtraining wires. If this operation is carried out manually, it is lengthyand difficult, since it is necessary to cut wire portions from a reel,surround the shoot to be attached and also the wire to which it is to beattached, and then perform the twisting of the loop thus formed in orderto ensure the closing of the latter.

To facilitate and speed up this tying operation, it was envisaged toproduce appliances ensuring automatic fitting, that is to say comprisinga body equipped with means for the feeding of continuous wire, fordelivering this wire to a curved jaw capable of being reclosed on itselfso as to surround the article or the like around which the tie is to betwisted, the body being equipped with a twister driven in rotationduring the twisting operation and with a device for cutting the wire inorder to form a tie. Such an appliance is described in the document FR 2738 56. This appliance comprises a single motor ensuring the variousfunctions of delivering the wire, of closing the jaw, of cutting a tieand of twisting the tie. However, the mechanism employed is complex, andthe power available for each operation is not always sufficient in viewof the use of a single motor.

SUMMARY OF THE INVENTION

The invention provides an appliance for the automatic fitting of twistedties, which possesses excellent reliability and a high power for theperformance of the various functions.

To this effect, the appliance to which it relates, of the abovementionedtype, comprises a first motor intended for carrying out the drive of thewire and the closing and opening of the guide jaw, and a second motorintended for actuating the twister and the wire cutting device, controlmeans being provided for successively controlling the drive of the wireand the closing of the jaw for guiding the latter, by means of the firstmotor, then, the first motor being stopped, the simultaneous drive ofthe wire cutting device and of the twister with the aid of the secondmotor, and, finally, after the stopping of the second motor, the openingof the guide jaw and the delivery of wire to the latter.

This appliance therefore comprises two electric motors, a first motorintended for carrying out simultaneously the drive of the wire and theclosing of the guide jaw, the article to be secured being surrounded atthe same time, and, in a second stroke and after the twisting of thetie, the reopening of the jaw and the delivery of wire up to level withthe latter. The second motor, functioning after the closing of the jawfor guiding the wire, ensures the cutting and twisting of the wirearound the article to be attached.

According to an advantageous characteristic of the invention, the jawfor guiding the wire comprises a first fixed part integral with the bodyand forming an open hook terminating in a zone in the form of an arc ofa circle, in which is mounted in a sliding and guided manner a secondpart displaceable between a first position, in which the second part isretracted into the first part of the jaw, corresponding to an openingposition of the latter, and a second position, in which the second partprolongs the first part of the jaw in order to form a closed loopencircling the article or the like around which the tie is to betwisted, a groove being formed on the inner face of the first and secondparts of the jaw in order to ensure the guidance of the wire as far asthe twister, after the formation of a loop.

It may be noted that, contrary to known appliances, the closing of thejaw around the article to be attached is not carried out by means of thepivoting of a movable part, but by means of the sliding of the movablepart in the fixed part in order to execute an encircling movement. Thisjaw is consequently suitable for attaching articles of relatively largediameter, for example up to 30 mm, while matching the diameter of thearticle to be tied, attachment taking place without excessive clampingand without bruising the article, this being particularly importantwhere plants are concerned.

In order to carry out the displacement of the movable part or secondpart of the jaw, that end of the second part of the jaw which remainsguided in the first part of the jaw, in the closed position of thelatter, has articulated on it one end of a first link which is arrangedlongitudinally to the body of the appliance and the other end of whichis articulated on a second link likewise articulated on the body andsubjected to the action of a spring tending to cause said second link topivot and to displace the first link in a closing direction of the jaw.

In order to control the pivoting movement of the second link in thedirection of a spring, the body has mounted on it pivotably about anaxis parallel to the axis of articulation of the second link on the bodya wheel which, driven in rotation by the first motor, is equipped, onone of its faces, with a cam coming to bear against the second link inorder to control the pivoting of the latter and consequently the openingand closing movements of the jaw.

The wheel has keyed on it a first pinion for driving in rotation from anelectric motor and a second pinion driving a pinion on which is keyed aroller for driving the wire, the wire passing between the driving rollerand a roller of parallel axis, free in terms of rotation and subjectedto the action of a compression spring, the latter roller performing thefunction of a pressing roller. There is a disengagement position,particularly during a period of prolonged nonuse of the appliance,making it possible to release the compression spring and prevent contactbetween the two rollers, the driving roller and the pressing roller, soas to avoid the risks of deformation attributable to prolonged bearingcontact.

According to one embodiment of this appliance, that end of the bodywhich is opposite that equipped with the jaw has mounted on it axially afirst electric motor, the output shaft of which drives, by means of apair of spur gears, a longitudinal shaft equipped with an endless screwmeshing with a pinion keyed on the wheel. Transmission by means of anendless screws ensures a smoother drive of the wire and greatermechanical reliability than when gearwheels are used.

According to another characteristic of the invention, that part of thebody which is located toward the jaw has mounted on it pivoting about anaxis oriented in the axis of the body, that is to say perpendicular tothe opening of the jaw, a shaft, on which are fastened the twister and acutting device, the twister being located toward the jaw and the cuttingdevice being located toward the interior of the body.

Advantageously, the twister consists of two bent and opposed arms in theform of a helix, and the cutting device is formed by two diametricallyopposed blades, the cutting edges of which are located in front of thecorresponding edges of the arms of the twister in the direction ofrotation of the twister and of the cutting device. When the second motoris put into operation, one blade of the cutting device being located infront of the corresponding edge of one arm of the twister in thedirection of rotation, the cutting of the wire is carried out in orderto form the tie, before the start of twisting. Moreover, the shape ofthe twister is particularly suitable for obtaining an attachment whichdoes not afford excessive clamping, this being advantageous where plantsare concerned.

According to one characteristic of the invention, the second electricmotor is mounted on the body in the central zone of the latter anddrives the twister and the cutting device by means of two pairs of spurgears.

Advantageously, this appliance possesses an electronic card for thecontrol of the electric motors, said card receiving information fromthree Hall-effect sensors, two of which are actuated by a magnetfastened to the wheel equipped with a cam and control respectively thestopping of the first motor and the putting into operation of the secondmotor, after the closing of the jaw and the stopping of the first motorat the end of the opening movement of the jaw, and the third of which isactuated by a magnet fastened to a drive gear of the shaft of thetwister and of the cutting device and, at the end of the twistingoperation, controls the stopping of the second motor and the puttinginto operation of the first motor.

It should be noted that, at the end of the twisting operation, thestopping of the second motor ensures the positioning of the shaftcarrying the cutting device and the twister, in such a way that thecutting edge of a blade is located in front of the corresponding edge ofthe twister in the direction of rotation.

Advantageously, this appliance comprises a selector determining thenumber of revolutions of the twister during a twisting operation. Withthe aid of the selector, the operator defines the number of revolutionsnecessary for carrying out the twisting of the tie, then exerts apressure on a contact button which triggers the sequence of operationscarrying out tying.

In view of the arrangement of the various component members, theappliance possesses an elongate general shape and takes the form of arod. This form is particularly ergonomic, since, under conditions ofuse, it limits the movements of the wrist, thus avoiding problems oftraumatism of the hand and of the forearm.

According to another characteristic of the invention, this appliancecomprises a double sheath for the delivery of the tying wire and of theelectrical energy for the motors. This arrangement makes it possible touse the appliance, whatever the climatic conditions, since the wire isprotected from moisture. Moreover, the training operation isfacilitated, since the wire is delivered positively and is not pulled bythe user. This protection of the wire prevents the entanglement of thetying wire and of the energy delivery wires and also the catching of thewire in branches. Finally, this arrangement protects the machine withrespect to the introduction of materials, such as earth, dust, wood orleaves, which would risk being caught on the wires, thus increasing thereliability and useful life of the appliance.

According to another characteristic of this appliance, the lattercomprises a device for recognizing the wire used, thus preventing thefunctioning of the appliance if the wire is not recognized as beingcompatible with the functioning of the appliance. This recognition ofthe wire used avoids the employment of wires which would not be suitablefor the appliance and which would be detrimental to its functioning orwould even risk damaging it.

BRIEF DESCRIPTION OF DRAWINGS

In any event, the invention will be understood clearly from thefollowing description, with reference to the accompanying diagrammaticdrawing which illustrates, by way of nonlimiting example, one embodimentof this appliance and in which:

FIG. 1 is a perspective view of the main components of this appliance inan exploded view, the hood which covers these various components notbeing illustrated;

FIG. 2 is a front view of the shaft carrying the twister and the wirecutting device;

FIG. 3 is a view in longitudinal section of this same shaft along theline III—III of FIG. 2;

FIG. 4 is a detail view of a card carrying sensors;

FIGS. 5 and 6 are two side views of the appliance in the open position,after engagement on an article to be tied to a support;

FIGS. 7 and 8 are two side views similar to FIGS. 5 and 6, respectivelyafter the closing of the jaw and before the twisting operation;

FIGS. 9 and 10 are two side views similar to FIG. 8, respectively duringthe twisting operation, after this operation and after the opening ofthe jaw.

DETAILED DESCRIPTION OF INVENTION

The appliance according to the invention comprises a body 2, on thefront part of which is mounted a subassembly comprising a jaw 3 intendedto surround the article to be attached and also the support to whichthis article is to be attached, and to the rear part of which arefastened a motor 4 and an electronic card 5. The assembly therefore hasan elongate shape intended to be covered by a hood having the generalform of a rod, which is particularly ergonomic for the user. The tyingwire 6 is supplied continuously from the rear of the body, passesthrough the body, at the same time being driven in the region of thelatter, and is delivered to the region of the jaw.

The jaw for guiding the wire comprises a first fixed part 7 integralwith the body and forming an open hook terminating in a zone in the formof an arc of a circle, in which is mounted in a sliding and guidedmanner according to this arc of a circle a second part 8 displaceablebetween a first position, in which the second part 8 is retracted intothe first part 7 of the jaw, corresponding to an opening positionillustrated particularly in FIGS. 5 and 6, and a second position, inwhich the second part 8 prolongs the first part 7 of the jaw, in orderto form a closed loop encircling the article or the like around whichthe tie is to be twisted. A groove, not illustrated in the drawing, isformed on the inner face of the first and second parts 7, 8 of the jaw 3in order to ensure the guidance of the wire 6 as far as the twister,after the formation of a loop.

The first motor 4 drives, by means of a pair of gears 9, 10, alongitudinal shaft 12 equipped with an endless screw 13. This shaft 12is mounted pivotably in bearings formed in the body 2. The endless screw13 meshes with a pinion 14. A wheel 15 equipped with a cam 16 is keyedon this pinion 14. The body has articulated on it, about an axisparallel to that of the wheel and at one of its ends, a link 17, on theother end of which is articulated one end of a link 18, the other end ofwhich is articulated on the second part 8 of the jaw 3. A torsion spring19 acts on the link 17 and consequently on the link 18 in order to causethe closing of the jaw 3. The cam 16 of the wheel 15 cooperates with thelink 17 in order to control the tilting movement of the latter towardthe closing position of the jaw, and to draw the link 17 into theopening position of the jaw.

The pinion 14 meshes with a pinion 20, on which is keyed a roller 22 fordriving the wire 6. The wire passes between the driving roller 22 and apressing roller 23 subjected to the action of a compression spring 24.There is a disengagement device 25 making it possible, under conditionsof prolonged nonuse of the appliance, to disengage the bearing contactof the pressing roller 23 against the driving roller 22, in order toavoid marking the two rollers as a result of prolonged punctiformbearing contact of one on the other. As shown particularly in FIG. 1,the body is equipped with a wire guide 26, the passage of the wire beingaccessible with the aid of an intervention flap 27. Mounted in front ofthe body 2 axially, that is to say perpendicularly to the opening of thejaw, is a shaft 28, on which are keyed a twister 29 and a device 30 forcutting the wire. As shown particularly in FIG. 2, the twister 29consists of two bent and opposed arms 32 in the form of a helix, and thecutting device is formed by two diametrically opposed blades 33, thecutting edges 34 of which are located in front of the correspondingedges of the arms of the twister in the direction of rotation of thetwister and the cutting device.

The drive of the shaft 28, equipped with the twister and the cuttingdevice, is carried out from a second electric motor 35 by means of twopairs of spur gears 36, 37. The appliance is equipped with a card 38carrying three Hall-effect sensors designated respectively by thereferences 39, 40 and 42. The wheel 15 is equipped with a magnet, thedisplacement path of which passes in front of the sensors 39 and 40,while the gear 36 is equipped with a magnet, the displacement path ofwhich passes in front of the sensor 42.

During the passage of the magnet associated with the wheel 15, thesensor 40 controls the stopping of the first motor 4 and the puttinginto operation of the second motor 35, after the closing of the jaw 3.The second sensor 39 controls the stopping of the first motor 4 at theend of the opening movement of the jaw 3. At the end of the twistingoperation, the third sensor 42 controls the stopping of the second motor35 and the putting into operation of the first motor 4. It should benoted that, when the appliance functions, the two motors 4 and 35 alwaysrotate in the same direction.

The appliance is equipped with a selector, not illustrated in thedrawing, making it possible to set the number of revolutions of thetwister during an operation, prior to a twisting operation.

Finally, as shown diagrammatically in FIG. 6, the appliance is equippedwith a double sheath 43 ensuring, on the one hand, the delivery of thewire 6 and, on the other hand, the delivery of the electrical supply 44.

The appliance functions as follows. Depending on the type of article tobe attached, the operator selects the number of twisting revolutions. Asshown in FIGS. 5 and 6, the operator engages the jaw in the openposition around the article 45 to be attached to a support 46. The cyclecontrol trigger, not illustrated in the drawing, is actuated. Theelectronic card 5 supplies a pulse to the motor 4 which comes intooperation. The motor drives the shaft 12 and consequently the wheel 15and the driving roller 22.

The cam 16 releases the link 17, retained up to then, thus ensuring theclosing of the jaw 3 as a result of the displacement of the movable part8 in relation to the fixed part 7.

The roller 22 for driving the wire rotates and causes the wire toadvance into the jaw 3, until the latter is engaged in the twister 29.

The motor 4 rotates until the magnet of the wheel 15 comes into positionopposite the sensor 40. The sensor informs the card 5 that the motor 4is to be stopped and that the motor 35 is to be put into operation.

The appliance is then in the position illustrated in FIGS. 7 and 8.

The motor 35 drives the shaft 28 carrying the twister 29 and the cuttingblade 30.

The cutting blade 30, in cooperation with a bedknife, severs the wire,and then the wings 32 of the twister catch the two strands of the wirein order to carry out twisting, as shown in FIG. 9.

The twister executes the number of revolutions defined by the user withthe aid of the selector. When the sensor 42 has counted the number ofrevolutions predetermined by the passage of the magnet fastened to thepinion 36, said sensor stops the motor 35, at the same time ensuring anexact positioning of the twister and of the cutting device for thepurpose of starting the next cycle. The information supplied to theelectronic card 5 likewise ensures that the motor 4 is put intooperation, still in the same direction, the wheel 15 ensuring, by meansof the cam 16, the drive of the link 17 in an opening direction of thejaw 3, as shown in FIG. 10. This rotational movement of the wheel 15 isstopped when the magnet which the latter comprises comes opposite thesensor 39. It should be noted that, during this opening movement of thejaw, the wire is driven by the driving roller 22, until, when the motor4 stops the movement of the latter, said wire reaches the end of the jaw3.

The appliance is then ready for another cycle.

It is possible to act on the appliance, should the wire no longer passthrough the guide channel 26. This action is carried out by means of theflap 27 provided for this purpose.

As may be gathered from the foregoing, the invention affords a greatimprovement to the existing technique by providing an appliance ofsimple and reliable structure which has great convenience for theoperator in terms of use.

1. An appliance for the automatic fitting of twisted ties on an article,comprising: a body; means for driving continuous wire; a jaw capable ofbeing reclosed on itself so as to surround the article, the wire beingsaid driven to the curved jaw and guided thereby; a twister driven inrotation during a twisting operation; a device for cutting the wire inorder to form a tie; a first motor for carrying out the driving of thewire and closing and opening of the jaw; a second motor for actuatingthe twister and the wire cutting device; and control means forsuccessively controlling the driving of the wire and the closing of thejaw, by means of the first motor, a stopping of the first motor and asimultaneous driving of the wire cutting device and of the twister bythe second motor a stopping of the second motor, and opening of the jawand delivery of the wire to the jaw.
 2. The appliance as claimed inclaim 1, wherein the jaw for guiding the wire comprises a first fixedpart integral with the body and forming an open hook terminating in azone substantially in a form of an arc of a circle, a second partmounted in a sliding and guided manner on the first part, the secondpart being displaceable between a first position, in which the secondpart is retracted into the first part, corresponding to an openingposition of the jaw, and a second position, in which the second partprolongs the first part, in order to form a closed loop encircling thearticle, and a groove formed on an inner face of the first and secondparts of the jaw in order to ensure the guidance of the wire as far asthe twister after the formation of a loop.
 3. The appliance as claimedin claim 2, wherein an end of the second part which remains guided inthe first part, in the closed position of the jaw, includes articulatedthereon one end of a first link which is arranged longitudinally to thebody and another end of the first link articulated on a second linkarticulated on the body and subjected to action of a spring causing saidsecond link to pivot and to displace the first link in a closingdirection of the jaw.
 4. The appliance as claimed in claim 3, whereinthe body includes a wheel mounted thereon pivoting about an axisparallel to an axis of articulation of the second link which is drivenin rotation by the first motor and includes on one face a cam coming tobear against the second link in order to control the pivoting of thesecond link and the opening and closing movements of the jaw.
 5. Theappliance as claimed in claim 4, wherein the wheel includes a firstpinion keyed thereon for driving in rotation from an electric motorwhich likewise drives a second pinion, on which is keyed a drivingroller for driving the wire, the wire passing between the driving rollerand a pressing roller of parallel axis, free in terms of rotation andsubjected to the action of a compression spring.
 6. The appliance asclaimed in claim 5, wherein an end of the body which is opposite the jawhas mounted on it axially the first motor, an output shaft of whichdrives, by means of a pair of spur gears, a longitudinal shaft equippedwith an endless screw meshing with the first pinion keyed on the wheel.7. The appliance as claimed in claim 1, wherein a portion of the bodylocated toward the jaw has mounted on it perpendicular to an opening ofthe jaw, a shaft, on which are keyed the twister and the cutting device,the twister being located toward the jaw and the cutting device beinglocated toward an interior of the body.
 8. The appliance as claimed inclaim 7, wherein the twister includes of two bent and opposed armssubstantially in the form of a helix and the cutting device includes twodiametrically opposed blades cutting edges of which are located in frontof corresponding edges of the arms of the twister in a direction ofrotation of the twister and of the cutting device.
 9. The appliance asclaimed in claim 7, further comprising an electronic card for thecontrol of the electric motors, said card receiving information fromthree Hall—effect sensors, two of which are actuated by a magnetfastened to a wheel equipped with a cam and control the stopping of thefirst motor and a starting of the second motor, after the closing of thejaw and the stopping of the first motor at the end of the openingmovement of the jaw, and third sensor being actuated by a magnetfastened to a drive gear of the shaft of the twister and of the cuttingdevice and, at the end of the twisting operation, controls the stoppingof the second motor and the starting of the first motor.
 10. Theappliance as claimed in claim 9, further comprising a selectordetermining the number of revolutions of the twister during a twistingoperation.
 11. The appliance as claimed in claim 1, wherein the secondelectric motor is mounted on the body in a central zone of the body anddrives the twister and the cutting device by means of two pairs of spurgears.
 12. The appliance as claimed in claim 1 comprising an elongategeneral shape and including a form of a rod.
 13. The appliance asclaimed in claim 1, further comprising a double sheath for the deliveryof the wire and of the electrical energy for the motors.
 14. Theappliance as claimed in claim 1 further comprising a device forrecognizing the wire used and for preventing the functioning of theappliance if the wire is not recognized as being compatible with thefunctioning of the appliance.